MIANYANG, China — Chinese authorities prepared on Saturday to drain a swelling lake formed by a devastating earthquake, completing work on a drainage channel to divert water that threatens hundreds of thousands downstream.

Officials are expected to discharge flood water from the lake into the channel between Sunday and Tuesday, the official Xinhua News Agency reported, quoting Yue Xi, deputy chief of the water and electricity section of the People's Armed Police.

The lake, called Tangjiashan, formed above Beichuan town in the Mianyang region of Sichuan province when a hillside plunged into a river valley during the May 12 quake.

Chinese authorities had evacuated nearly 200,000 people by early Saturday and warned more than 1 million others to be ready to leave quickly if the lake floods.

The confirmed death toll from China's worst quake in three decades was raised Saturday to 68,977, an increase of about 120 people from a day earlier. Another 17,974 people were still missing, the State Council, or Cabinet, said. The daily increase was the smallest since the government started announcing death tolls shortly after the quake hit.

Xinhua said "a total of 197,477 people were evacuated to safe ground as of 8 a.m. Saturday." It did not say how the number was determined. Some of the people may have been in the path of the planned runoff.

State television showed bulldozers and other heavy earth-moving equipment working on the water diversion channel. It did not show how far up the landslide the channel had been carved.
Xinhua said Tan Li, the Communist Party chief of Mianyang, had issued another order for all 1.3 million people in the area to be evacuated if "the barrier of the quake lake fully opens" and floods the area.

There was no sign that the banks of the lake were about to burst. Troops have sealed off Beichuan to the public.

Tangjiashan is the largest of more than 30 lakes that have formed behind landslides caused by the quake, which also weakened man-made dams in the mountainous parts of the disaster zone.

Millions living in tent campsMillions of people in Sichuan are already living in tent camps and prefabricated housing, which have taken on the tone of new villages.

In Mianyang, about 200 families left their camps in flood-prone areas of the city and moved to higher ground in a wooded park on Fule Mountain. Most had camping tents and shelters made of tarps pitched under trees amid ornate gazebos and tea houses with traditional sloping yellow-tiled roofs. Red signs on the buildings said, "Dangerous building, don't come near."

One woman who only gave her surname, Wang, said life was uncomfortable but fine under the circumstances.

"We've got all the basics. Those who are out of work are being given food, but my company is taking care of me," said Wang, who was living in a camouflaged tent set above the ground on wood planks.

One man, who also gave only his surname, Zhang, said he has been unhappy since moving to the camp two days ago.

"We were living near the river and the Mianyang officials got on TV and said the area was dangerous because of possible flooding and we were ordered to move here. They promised they'd take care of us, but we've been given no food, no tents," he said, pointing to the simple structure of tarps his family of three was living under. "I had to rig this up myself. We've just been eating instant noodles and bread that we brought ourselves."

Nearby, a woman selling tomatoes, green peppers and eggplants along the narrow park road was loading the vegetables back on her three-wheel motorcycle cart. "I'm packing things up because no one is buying," she said. "They have no pots or pans. No way to cook the food."

Meanwhile, the military lost contact Saturday with a helicopter flying earthquake relief missions in Sichuan province, Xinhua said.

The agency's brief reports didn't say how many people were aboard the aircraft. A government-ordered search was under way, it said.

Checking on relief effortsXinhua also reported that President Hu Jintao arrived Saturday to check on relief efforts in Shaanxi province. He was shown on state TV at a shelter talking to children who had been left homeless by the earthquake.

Just to the north of Sichuan, Shaanxi also suffered damage in the earthquake.

Another province hit by the earthquake, Gansu, plans to complete its rebuilding by the end of 2010, the governor said Saturday.

The rebuilding will include homes, schools and hospitals and the restoration of infrastructure such as telecommunications, power supply and transport, Xu Shousheng was quoted as saying by Xinhua. The earthquake killed more than 360 people in Gansu.

Numerous fundraising events have been held around China, with the latest planned for Tuesday when Chinese pianist Lang Lang and the Philadelphia Orchestra are to play a nationally televised charity concert in Beijing to support the earthquake relief effort.

The orchestra is in China to commemorate the 35th anniversary of a 1973 trip it made as the Cold War between China and the United States began to thaw.